1. Field of the Invention
The present invention relates generally to telephone call processing. More specifically, the present invention relates to processing requests to transfer a telephone call in an efficient manner.
2. Background of the Invention
The ability to transfer telephone calls is a common and popular feature in conventional telephone call processing systems. For example, calls to call centers are often transferred to agents who can assist the caller. In another example, a receptionist typically answers telephone calls to an office, and then transfers the calls to the intended party.
With today's ever-increasing use of mobile telephony, the ability to transfer a telephone call from a landline to a cellular telephone is likely to find great use. For example, assume a calling party establishes a telephone call with a called party using a landline telephone in her home. During the telephone conversation one of the parties decides to leave her house, but she does not want to disconnect from the current telephone conversation. If she could subscribe to a transfer service, she could transfer the telephone call from her landline phone to her cellular telephone.
To appreciate the value of the present invention, an understanding of conventional call transfer methods is provided. To perform the transfer the transferring party (for example, the calling party), interrupts the current call. This interruption is typically provided by the transferring party performing a hook flash to signal a switch in a telephone company central office that services the transferring party's telephone that the transferring party desires to perform mid-call processing of the telephone call. In this case, the mid-call processing is transfer of the telephone call. In response to the hook flash, the switch provides a dial tone to the transferring party as a prompt for the transferring party to dial a transfer telephone number. The transfer telephone number is the number to which the telephone call is transferred. After the telephone number is entered, the switch causes the telephone associated with the transfer telephone number to ring. This telephone is answered. If the transferring party thereafter hangs up, the call is successfully transferred. If the transferring party remains on the line, the call becomes a three-way conference call. To remain on the line, the calling party generally performs a hook flash instead of hanging up the telephone.
Another known mechanism for transferring telephone call is by using ISDN-capable telephones. The ISDN implementation is similar in function to the transfer described above. However, control of the transfer is accomplished via out-of-band signaling, rather than by using a hook flash as described above. Typically, a transfer button is provided on the ISDN phone. To transfer an active telephone call using an ISDN telephone, the user typically presses the transfer button. This causes a message to be sent to a central office switch. The switch detects the message and provides a dial tone to the user in response. The dial tone is a prompt to the user to enter a transfer telephone number. The user enters the transfer telephone number. The switch receives the transfer telephone number and causes a call to be completed to that number to cause a telephone associated with the transfer telephone number to ring. When the telephone associated with the transfer telephone number is answered, the user can hang up to complete transfer of the telephone call.
Another type of telephone that can be used to transfer telephone calls is a programmable phone such as an analog display services interface (ADSI) telephone. An ADSI telephone is essentially an analog telephone that has a screen. The screen contains one or more soft buttons. A user can select a soft button to perform a function. One of the buttons can be a transfer button. When the user selects the transfer soft button, the ADSI sends a hook flash to a central office switch. As described above, in response, the switch provides a dial tone to the user as a prompt to enter a transfer telephone number. The switch collects the digits of the transfer telephone number entered by the user and completes a telephone call to a telephone associated with the transfer telephone number, causing the telephone associated with the transfer telephone number to ring. When the ringing telephone is answered, the user of the ADSI telephone typically presses the transfer button again or hangs up the phone to disconnect from the original telephone call, thereby completing transfer of the telephone call to the telephone associated with the transfer telephone number.
At significant drawback associated with conventional mechanisms for transferring telephone calls is that numerous digits must be entered to transfer the telephone call. For example, in many cases at least 10 digits will have to be entered. Dialing numerous digits in this manner can be cumbersome and prone to error.
Another significant problem with conventional transfer of telephone calls is the possibility of transferring a toll call thereby losing control over the duration of the telephone call. For example, if the transferring party transfers a call for which they are paying, they will continue to be billed for the telephone call despite the transfer. Thus, by virtue of transferring the telephone call, the transferring party no longer has control over its duration. This can prove to be inconvenient and costly to the transferring party. For this reason, residential telephone customers are not generally able to order the transfer feature.